Encephalomyocarditis virus (EMCV) is a cardiovirus within the Picornaviridae family. EMCV behaves as an enterovirus in rats, the most common carriers of the virus, as EMCV persists in the gut of these animals for extended periods of time. (Acland, H. and Littlejohns, I.; "Encephalomyocarditis", Diseases of Swine, editors, Leman, A., et al, The Iowa State University Press, 1981, page 339-343). The host range is very broad and includes primates, mice, elephants, squirrels and swine.
Populations of swine, particularly young pigs, are extremely susceptible to EMCV. The virus causes a variety of disease syndromes, including reproductive losses resulting from stillborn, mummified or weak pigs at farrowing. (Links, I., et a., (1986) Aust. Vetern. J. 63:150-151). When suckling or young feeder pigs are infected by the virus, mortality may occur as the result of clinical encephalitis, myocarditis or pneumonia. (Link, supra, and Littlejohn, I., (1984) Aust. Vetern. J. 61:93). Clinically ill pigs that do not die become inefficient feeders, resulting in performance losses in fattening pigs.
Currently, there is no known treatment for an EMCV infection in swine and prevention appears to be limited to the control of rodents on pig farms. (See Acland, supra). The instant invention provides a more effective and efficient means of preventing an EMCV infection in pigs.